School of Mechanical and Electrical Engineering, China University of Petroleum China United Coalbed Methane
Company Limited

为了提高非常规油气生产的经济效益,通过对部分地区的叠置型煤系气进行合采作业以提高其产量,因合采过程中不当的工艺会产生较为严重的层间干扰现象,为此开发出适用于煤系气合采作业的工艺,据压力体系不同将合采工艺分为同压力体系合采、分压力体系合采及负压合采等工艺,利用GRAY压降模型及伯努利方程得出了3种工艺相应的合采地层条件,结合不同类型煤系气组合地层特征,分析各类叠置煤系气地层所适用的合采工艺,提出了不同压力体系下合采工艺的适用条件。研究结果表明:不同煤系储层下压降梯度的差异显著将导致同压力体系合采工艺在煤系气合采作业过程中限制较大;负压合采工艺的地层要求较为苛刻,只适用于高产气低产水的煤系气合采组合;分压力体系合采工艺适用性较强,在合理构建井下空间的基础上满足任意情况下的煤系气合采作业。

In order to improve the economic benefit of the non conventional oil and gas production, a co-mining operation was conducted in the overlay type coal m easures gas stratum in a part area to improve the production. During the co-mining process, a improper technique would possibly cause a serious interference phenom enon between the strata. In order to study the technical features suitable to the coal measures gas co-mining operation, according to the different pressure system, the co-mining technique could be divided to a co-mining technique with a same pressure system, a co-mining technique with a different pressure system and the co-mining technique with a negative pressure system and in combination with a GRAY Pressure Drop Model and the Bernoulli Equation, the relevant co-mining condition suitable t 0 the three techniques was obtained. With the different type coal measures gas combined strata features, the paper had an analysis on the suitable co-mining technical features of each overlay coal measures gas stratum and provided suitable analysis on the co-mining technique under different pressure system. The study results show ed that under the different coal measures reservoir, the obvious difference of the pressure drop gradient would cause the co-mining technique with the same pressure s ystem could have a high application restriction in the coal measures gas co-mining operation process. The strata requirements of the negative pressure co-mining techn ique would be drastic and would be only suitable for the combination of the high gas production and low water production coal measures gas co-mining.The co-mining t echnique with different pressure system would be high and based on the rational construction of the underground space and could ensure the co-mining operation of th e coal measures gas under the any condition.